Positive:
1. As IDE, Android Studio with Gradle (for build) being used.
2. Android Architecture is being followed with Application Class
3. Smack xmpp is being used which is most popular library for chat apps.
4. Emoticons lib has been used which will make it to work on all different flavours of devices.
5. Volley has been used for network communication and ion library for images ,which are recommended libs
6. AppCompact ver 7 has been used which is recommended.
7. Crashlytics being used for crash reporting.